The NAM Conus seems to be OK this morning using 10.7.10

The NAM download works ok in large area downloads.  But try downloading an area of just most of Long Island Sound -- you get the whole country.  Same for HRRR. But GFS works properly.

For example, try the Expedition/NOAA HRRR or NAM for a download of one day, wind only, default hour steps of Long Island Sound from Stamford to New Haven, Connecticut -- the whole country file is downloaded.
For a few runs it seemed that having Chart Bounds and/or Image Bounds selected to show was causing the problem, but now the problem happens with or without that selection.  Again, the GFS downloads are fine.

If you extend the selection from, say, Trenton to past Block Island, the download is fine (although slanted and not conforming exactly to the rectangle chosen). See image.

Using version 10.7.9, Windows 7 Pro.

 

Nick,

i've done a little more work on this subject of NAM and HRRR giving me a firehose of data when a small area request is made.

Using NOMADS on the Web for the high resolution NAM grib request, the system will allow me to download a very small area. Making a request using Expedition for the same area sends the whole NAM file down the pipe, tens of megabytes.

For example, requesting of NOMAD the area from 40N73w to 40.1N73.1W works fine, sending a Grib2 fie of less than 1 kb.

Requesting the same area through Expedition results in getting the whole continental USA, a 54 megabyte file.

Now an area that tiny is not much use, but Expedition doesn't seem to work for an area less than a full degree wide and high, approximately, which is larger than is sometimes needed for a spot update.

When out on the boat, it really burns the air time to get tens of megabytes when only tens of kilobytes are needed.

So there must be something lost in translation between drawing a small box in Expedition and sending a server request to NOAA/Nomads (or however the system does it) that results in a big download instead of a tiny one.

This issue might also fix some of the reported "hangs" experienced when requesting NAM or HRRR data, since with a low bandwidth system it would take forever to finish the download.

Thanks!

Nick,

Bingo!  Expedition rounding the area request to the nearest degree would cause the problem I am seeing.

Requesting an area where either the Longitude or Latitude bounds round to the same number causes a system error within Nomads. The Nomad system then gives up and just sends you data for the whole continent!

Brilliant, Nick, thanks!

DM